Abrading apparatus



May 3, 1938.V w. L. KEEFr-:R 2,116,152

ABRADING APPARATUS' FiledFeb'. e, 1955 4 sheets-sheet 1 May 3, 1938. w.L. KEI-:FER

ABRADING APPARATUS Filed Feb. 6, 1955 4 Sheets-Sheet 2 y May 3, 1938.

w l.. KEEFR 2,116,152

ABRADING APPARATUS Filed Feb. e', 1935 4 sheets-snee; 5

m www WW` May 3, 1938. w. KEEFr-:R 2,116,152

ABRADING APPARATUS VFiled Feb. e, 1955 4 sheets-sheet 4 Wr/nn. @my

Patented ely 3, i938 UNiTED l.STATES ABRADTNG APPARATUS Walter L. Reefer, Hagerstown, Md., assignor to Pangborn Corporation, Hagerstown, Md., a corporation of Maryland Application February 6, 1935, Serial No. 5,270 i Ato claims.

The present invention relates to abrading apparatus, and it is more particularly concerned with apparatus for centrifugally 'propelling or projecting abrasives. Y

In its preferred embodiments, my improved abrading apparatus takes the form of a rotating mechanism which is operable to propel or discharge abrasive from a limitedl peripheral region of the mechanism, and which may be employed to yreplace air-blast abrasive propelling apparatus in abrading mechanisms. Although apparatus of this general character is in use and represents a substantial advance in the art overthe early centrifugal blasting apparatus in which the abrasive is discharged throughout three hundred and sixty degrees of the wheel or other rotatable mechanisms, such prior apparatus is subject to rapid wear.

The most commonlyfused of such prior apparatus is provided with a bladed wheelhaving an abrasive feed conduit with a restricted abrasive outlet and agitator in its center, while other forms feed the abrasive into the paddles from one sidein a manner to control the direction of abrasive discharge. However, the abrasive discharge from such prior centrifugal wheels hasv not been positively restricted to a limited region with the result that stray abrasive is discharged in sumcient quantities to rapidly abrade the wheel housing, reducing the' eiliciency of the Wheel, and increasing the costs of maintenance and operation. It has also been found that the blades of both the Wheels and agitators of such prior apparatus wear out rapidly which not only entails considerable expense for new blades, but

` also involves a loss of valuable time,` as the maoperable to vary the width of the stream.

chine must be practically dismantled every time the blades are replaced.

My apparatus overcomes all oi the defects of such prior apparatus, is constructed in an entirely different manner, and operates in accordance with basically different principles from the prior apparatus, and which will become apparent from the following objects. l

It is a major object of my invention to provide a centrifugal device for propelling abrasives which is of simple construction and which will have a materially longer `useful life than apparatus of this character heretofore proposed.

It is another important object of my invention to provide an apparatus for mechanically propelling abrasives' which is so designed that the abrasives pass through the apparatus to the' `discharge area at low velocity, thereby reducing abrasion of the parts to a minimum.

(o1. n si i It is another major object of llny invention to devise a mechanical abrasive-propelling apparatus having a rotatable mechanism which is `operable to' discharge abrasive from a predetermined limited peripheral region thereof, and to positively prohibit abrasive discharge from any 5 other region.

My invention further aims to provide a mechanical abrasive-propelling apparatus having a rotatable head which will automatically close'10 during apart of each operating cycle and maintain abrasives in the head, and which will automatically open up Aand discharge abrasives from the head during another part of each cycle of operation.

A further object of this invention is to provide an abrading apparatus having a rotatable mechanisrn which will impart substantially solely tangential velocities to abrasives supplied thereto.

Another object of my invention is to provide a mechanical abrasive-propelling apparatus hav- '20 ing the parts by which the abrasives are propelled,` constructed of rubber, whereby destructive abrasion thereof in operation is reduced to a minimum. *I

My invention further aims to provide a mechanical abrasive-propelling apparatus which may be quickly and easily disassembled and the parts which are subjected to abrasion during operation, readily replaced -in a minimum of 3o time.

A further object of this invention is to provide a 'centrifugally operable abrasive-propelling apparatus having a rotatable head from which the abrasive is discharged in a stream of predetermined angular width, and which is selectively It is a still further object of my invention toV provide a mechanical abrasive projecting apparatus having a rotatable head, all portions of which will open up once every revolution when -Y they-pass a predetermined point and allow the sive's having a sealing element for preventing 50- improper abrasive discharge from the apparatus, and which automatically adjusts itself to compensate for wear of. the sealing element. Further objects of my invention will become apparent as the specification 'proceeds in-con- 55 nection with the accompanying drawings, and from the appended claims. In the drawings:

Figure 1 is a top plan view of the preferred form of my invention.

Figure 2 is an elevational end view of the machine iliustrated in Figure 1 as it appears when viewed from the right hand end of that figure.

Figure 3 is an enlarged longitudinal sectional view of the machine illustrated in Figures 1 and 2, and is taken substantially on the line 3-3 of Figure 2. looking in the direction of the arrows.

Figure 3A is a fragmental sectional view taken substantially on the line 3A-3A of Figure 3.

Figure 4 is a view similar to Figure 3, but is taken along the line 4-4 of Figure 2, looking in the direction of the arrows.

Figure 5 is a i'ragmental perspective view of the driving runner of the apparatus illustrated in Figure 1 and shows the ring and ring groove.

Figure 6 is an enlarged fragmental sectional view of runners and the ring and ring grooves of 'the apparatus illustrated in Figure 1 and shows the action of the rings as they undergo movement from open to closed position.

Figure 7 is a fragmental sectional view of a modiiied form of my invention and illustrates a modiiied ring and groove assembly incorporated in the apparatus shown in Figure l.

Figure 8 illustrates another form of abrading apparatus, also forming part of my invention.

Figure 9 is a fragmental elevational view of the rubber rings employed in the device shown in Figure 8 and illustrates them as they appear when removed from the machine.

Figure 10 is a fragmental sectional view of another form of abrading apparatus, also forming part of my invention.

Figure 11 is a view similar to Figure 10Y but illustrates a further modied form of my invention,

Figure 12 is-an elevational view of a modified form of sealing ring assembly and which may be used in the apparatus illustrated in Figures 8, 9, 1I) and 11, and` Figure 13 is a fragmental sectional view similar to Figure 4, but illustrates a pneumatically operated mechanism, also forming part of my invention, for replacing the spring assembly of that ligure. A

With continued reference to the drawings, wherein like reference characters have been used to designate like parts throughout the several views thereof, and with particular reference to Figures 1 to 6, my abrading apparatus or blasting machine generally consists of a base A, upon winch a driving runner B and a driven runner C are rotatably supported. A resilient sealing ring assembly D is disposed between the driving and driven runners and functions to prevent the abrasive from leaving the chamber dened by the runners except at one discharge point. Abrasive is introduced into the device,

either by gravity or by pneumatic means, by way of a funnel E. The driving and driven runners are urged towards each other, so as to clamp rings D between them, by means of a spring assembly designated as F.

Supported upon base A, in any suitable manner, are bearing assemblies I0 and II which may assume any desired form. In the present instance each bearing assembly preferably consists of a ball bearing I2 and a pair of sealing assemblies I3, which retain lubricant in the bearings and also prevent abrasive contained in the atmosphere from getting at the bearings. Journaled in bearings I0 and I I is a shaft I4. Power may be applied to shaft I4 in any suitable manner, but in the present instance I have illustrated a pulley I5, with which a belt drive may be associated.

The upper portion of my apparatus is preferably enclosed by a housing I6, which assumes a substantially semi-cylindrical conguration and is preferably equipped with inspection doors I1. Doors I'I are secured to housing I6 in any suitable manner as for instance by means of links I8 and thumb screws I9. Cover I6 is pivotally secured to base A, and to this end it is provided with a handle 2U and a pair of ears 2I. Ears 2| are aligned with a pair of similar ears 22 formed on a plate secured to base A and are plvotally connected thereto by means of a pin 23. Pin 23 is secured against displacement with respect to cover I6 by means of a pair of set screws 24 threaded into ears 2|. The free end of housing or cover I6 is secured down to base A by means of a stud 26 pivoted to base A, and a nut 2'I engaging the upper sides of a pair of ears 28 provided on cover I6. Nut 2'I may be removed and cover I6 swung upwardly about pin 23 as an axis to give access to the interior of the machine for a purpose that will presently appear.

The driving runner or rotor will now be described. Secured to a shouldered extremity 3I of shaft III, byany suitable means such as a key 32, is a driving runner 33, which preferably assumes a disk-like congurat-ion. Secured to driving runner 33, by means of a plurality of circularly spaced machine screws 34 are two distributor plates 35 and 36. Distributor plates 35 and 36 are utilized to smoothly distribute the abrasive throughout 360 of the runner and are also employed to bring the abrasive, which enters the machine in a non-rotative condition, progressively up to the rotative speed of the runner periphery in gradual stages. Plates 35 and 36 are provided with a plurality of annular flanges or projections 38 and 39 respectively which cooperate with each other to define a tortuous or corrugated passage 4I, which extends from'a region near the axis of the machine outwardly towards the periphery. Plates 35 and 36 have fins 4D and 40a for accelerating the abrasive. Circular lips or flanges 38 andv39 have their faces which are disposed toward the axis of the mechanism inclined at an angle which is less than the angle of repose of the abrasive, with the result that a stationary layer of abrasive builds up upon the inner face of each lip. As the lips further away from the axis of the mechanism possess a greater peripheral speed, and are of greater circular area than those closer to the axis, it is apparent that the abrasive must not only be accelerated as it passes outwardly over the distributor plates, but it must also be smoothly distributed, or spread out over the lips. As a stationary layer of abrasive is always located on the lips during operation of the machine it is apparent vthat they are pro- I tected from excessive wear. Although I have il lustrated, and prefer to secure both distributor plates to the driving runner, it is apparent that one or both of the distributor plates may be carried by the driven runner if desired without departing from the spirit of my invention.

Distributor plate 35 is supported within'an annular face 42 formed on driving runner 33 and terminates short-of the periphery thereof. Boss 43 is cut away to define a sealing-ring receiving groove denoted' generally as 44.

With reference to Figure 3 of the drawings,

it is apparent that the outer periphery of distribgrooves or recesses 5| into which extraneous or amarte utor plate defines one wall of groove 44, so that the runner is not subjected to the action of the abrasive. Groove 44 is provided with a curved portion 45, a. substantially flat rear wall 4B, a curved portion 41 and a portion 48 which is sub'stantiallystraight in section. Curved portion 41 and straight portion 48 are joined by a substantially straight portion 49, which functions as an inclined plane in a manner that will be presently described. v

Straight portion 49 of groove 44 with a plurality of circumferentially extending stray abrasive is adapted to be deposited. Communicating with the bottom of each groove 5| at spaced intervals about theperiphery of runner 33 are a plurality of drain holes 52. Abrasive finding its way into grooves 5| is adapted to drain into holes 52 and be centrifugally discharged from the rotor head in a manner to be presently set forth. Also communicating with each groove 44 at spaced intervals about the periphery of the runner 33 are a plurality of apertures 53 which are employed to relieve any air pressure conditions developed in the groove in a manner to bepresently set forth. Distributor plate 36, adiacent its periphery,v (Figure 3A) ls 'i also provided with a plurality of spaced teeth paratus.

53' which insure that abrasive leaving the latter will possess a rotative speed as great as that of the distributor plate assembly.

Disposed substantially loosely in groove 44 is a ring) 54, which is adapted to cooperate with a similar ring carried by the driven runner and control the discharge of abrasive from the ap- Ring 54 may be constructed of any suitable material that has the flexibility and the sealing properties required of it in practice,v for instance, rubber covered fibre or metallic rope, or -a steel wire' or a metallic reinforced fabric or rubber material may be used. In the present instance, however, it is preferably constructed of A a comparatively soft grade of rubber without reinforcing means of any character. The operation of ring 54 will beset forth in detail hereinafter. The driven runner` will now be described.

A driven runner 51 is mounted for rotation in a bearing assembly to be hereinafter described and its axis is ldisposed ata predetermined angle 58 with respect 'to the axis of the driving' runner.

The driven runner is provided with a smooth cylindrical portion 59 which cooperates with a groove 6D formed in the inner edge of distributor plate 36. A plurality of radially extending passages 60' communicate with groove 60-and function to convey any abrasive finding its way between portion 59 of the driven runner and plate 35, to the innermost groove o f the latter. The driven runner is provided with va comparatively long hub 6|, whose internal surface is preferablysmoothly finished and assumes the shape of a gradually flared cone 62.- The small portion of the driven runner hub is provided with a removable member 63, which has a surface conforming to surface 62 and which maybe removed after it has become worn in service. If

desired 'the entire inner surface of the driven runner may be made in the form of a removable wear plate, but it has been found that as the stationary abrasive initially contacts the driven ruimer inthe region of member 63, the greatest abrasion occurs in this region, and a wear plate is accordingly only necessary at this point.

The outer periphery of the driven runner is is provided' runner, are a pair of bearings 12 and 13, a

Vspacer member 14 and .a third hearing l5. Al-

though the bearings may assume any desired form, ball bearings are preferably employed and in this connection it is observed that bearings 12 and 15 both cooperate` to resist axial movement of the driven runner to the right (Figure 3) and that bearing 13 absorbs thrusts in the' nut 1| threaded on the small end of the driven V other direction. .The thrust capacity propendery ates in one direction for the purpose of absorbing the centrifugal action of 'rings54 and 61. As this type of ball bearing is capable of sustaining an axial load that is substantially as great as `its radialload-carrying ability, it is seen that the driven-runnerA is adequately supported for both radial and axial loads.

Bearings 12 and 13 are mounted in an axiallyv slidable sleeve-11 and bearing Al5 is supported 'in aspacerysleeve 18 having an oil baille 19 j formed thereon. The left hand end of sleeve 11 is provided with an inwardly directed ange 8|, which serves to prevent the lubricant from being lcentrifugally thrown from the bearings A ring 82 encircles sleeve 11 and the bearings and spacer 18 are clamped against axial movement in sleeve 11- against ring 82 by means of an end plate 83, which is in turn secured to sleeve 11 by means of cap screws 84 or the like Mounted in a bore in the end of end plate 83 is a packing assembly 85 which cooperates with the outer surface of the driven runner hub and is secured in place by means of a nut 8B threaded into the end plate.

The driven runner is accordingly mounted for rotation in sleeve member 11 and the latter is mounted for axial movement so as to move the driven runner toward and away from the driving runner by means Vof a support 88, which'is secured to cover |5 by means of cap screws 89 or the like. 4.A plurality of shims 9| are preferably disposed between support 88 and cover I6 for a purpose that will be pointed out hereinafter.

In order to prevent abrasive from nding its way between support 88 and the end of sleeve 11,

a flexible shield is secured to theV respective members by means of wires 96 and 31, which force the ends of shield 95 into grooves located in these members. Abrasive is prevented from finding its way into the bearings by a cylindrical shield 98' which is secured to the driven runner by means of cap screws 39. Base A fits shield 98 rather closely, but in order to prevent any abrasive that: may' get between the parts from working into the bearings, a drain hole llll is provided in the base member through which the abrasive may gravitate out of the machine.

A sealing member |02 tightly engages the bottorn portion of support 8B -at |83 and is secured to the upper portion of support 88 by `means of cap screws |84. Member |02 sealingly cooperates with the outer surface of member 98, and in order to prevent abrasive from working b`eA tween these two members the outer surface. of

v my invention.

member 98 is provided with a screw thread |05. which is given the proper pitch to cause abrasive which finds its Way between the parts to move to the left and outwardly of the members.

Sealing members 98 and 85 accordingly cooperate with hub 6| of the driven runner and support 88 so as to dene a iluid tight lubricant chamber, with the result that the bearings may be packed with lubricant when they are assembled and therefore lubricated throughout the life of the machine. If desired however, a grease tting may be associated with the parts so that additional lubrication may be periodically supplied.

Abrasive may be introduced into the interior of the driven head in any suitable manner, but I preferably employ a hopper or funnel member |06, to which a plate |01 (Figure 2) is secured. Plate |01 is secured to the rear face of cover plate 83 by means of two of the screws 84 thereof. Abrasive may be introduced into funnel |06 in any suitable manner, but I preferably allow it to drop by gravity therein from a suitable metering valve which supplies it at a predetermined rate. If desired however, it may be pneumatically carried into funnel |06 or be otherwise introduced Without departing from the spirit of Moreover funnel or spout |06 may be given a suitable configuration, or suitable pneumatic means may be employed to cause the abrasive to spiral in the direction of rotation of the driving and driven runners as it enters hub portion 6| of the driven runner, in order to reduce the velocity difference of the abrasive and the runner at the instant of initial' pick-up, and thereby reduce the abrasion that occurs at this point.

'I'he driven runner is preferably urged toward the driving member, and although any means may be employed for this purpose, I preferably make use of a device which is located exteriorly of the mechanism, so that it may be readily adjusted-and it takes the form of a resilient tensioning mechanism. This mechanism will now be described.

With particular reference to Figure 4, an apertured lug |09 is preferably integrally formed on end plate 83 and a threaded member Ill, which will be hereinafter termed a screw, extends loosely therethrough. Screw is threaded into a cup member I2, which is preferably constructed of bronze and has a closed bottom for the purpose of preventing abrasive from being introduced between the threads of members and H2. Cup member ||2 is in turn threaded into a boss or enlarged portion ||3 provided on support 88, and is adapted to be locked therein by any suitable means such as a latch |||i and a cap screw ||5. Aratchet member ||6 is snugly fitted on screw and is preferably locked thereto by means of a pin ||1. Rachet member ||6 is equipped with an indicating line H8, which will be termed a hair line. Line ||8 cooperates with a similar hair line ||9 provided on a. latch member |2I. Member |2| is pivoted on a pin |22 located in a pair of ears |23 formed on lug |09. Latch I2| is adapted ,to be selectively engaged in any one of a plurality of notches |24 located in ratchet'member ||6 for locking screw against movement in its various adjusted positions.

Bearingagainst the rear face of lug |09 is a cup |26. Screw ||I extends through cup |26 and is encircled by a compression spring |21 which acts against the bottom of the cup and reacts against a. washer |28 and a nut |29 threaded on screw The end of screw is provided with a square portion |3l, in order that it may be engaged with a wrench and turned so as to adjust the parts in a manner that will be presently set forth.

From the structure just described it is apparent that spring |21, acting through cup |26, lug |09, and end plate 83, urges sleeve 11 to the left, to thereby urge the driven runner toward the driving runner and thereby urge ring 61 into engagement with ring 54. It is also apparent that the force with which the driven runner is urged toward the driving runner may be adjustably varied, either by lifting latch |2| and rotating screw or by tightening nut |29, both of which serve to increase the pressure of spring |21. The force with which the driving and driven runners are urged together directly controls the mode of operation of the machine and I have provided two independent means for increasing or decreasing this pressure in order to simplify the adjustment of the machine, as will presently appear.

Although I have illustrated a resilient means located exteriorly of the machine for urging thel driving and driven runners toward each other, and I prefer to use this organization for the reason that it may be readily adjusted while the machine is in operation, it is to be understood that if desired, springv |21 and the associated parts may be omitted or be supplemented by a plurality of springs directly associated with the driving and driven runners without departing from the spirit of the present invention. For instance, axially extending studs may be secured to the driving runner and extend through apertures in the driven runner, and compression springs may be associated with the studs so as to bear against the rear face of the driven runner and nuts threaded on the studs, so as to thereby urge the parts toward each other, and the appended claims are intended to embrace my device when it assumes this form. It is also to be understood that although I have illustrated and prefer to employ a driving and driven runner assembly wherein the driving connection is provided therebetween by virtue of frictional engagement of the rings carried by the respective members, a direct mechanical connection may if 4desired be provided between the driving and driven runners, without departing from the spirit of my invention. Moreover, power may be applied to both runners if desired.

The operation of my device so far described will now be set forth.

The apparatus as it is shown in Figure 3 illustrates the parts as they appear when operating at their normal running speed, and under these conditions hair line ||9 of latch |2| aligns or registers with hair line ||8 of ratchet member H6. When the machine is stopped a difierent condition exists, and before describing the relation of the parts of the tensioning device, it will be assumed that the machine is stopped and that boss |09 is held in engagement with ratchet member ||6 under the iniiuence of spring |21.

With reference to Figure 3, it is observed that by reason of the angle 58 between the axes of the driving and driven runners, the tops of the runners are disposed closer together than the bottoms thereof. This causes the chamber defined by the runners to be closed at the top and open at the bottom. For the sake of brevity, these sides will be respectively termed the closed and open` sides.

As the machine'is started from rest and attains normal running speed, which in the present instance is in the neighborhood of 2400 R. P. M., rings 54 and 61 are acted upon by centrifugal force and tend to roll down their respective inclines 49 and 49a. The portions of the rings on the open side of the runnersroll down into contact with, and are stopped by flat portions 48 and 88a. The rings are thereby maintained in spaced relationship to allow abrasive to be centrifugally discharged' from'the mechanism, and as seen in Figure 6, therubber is somewhat' deformed into surface-contact with these suriaces'by virtue of the considerable centrifugal force acting upon the rings.

Under the conditions just described, the por-'f tions of rings 54 and 61 which are disposed on the closed side of the apparatus, which in this instance is the upper portion of the runners, are also acted upon by centrifugal forces of equal magnitude, but as the peripheries of the driving and driven runners are more closely disposed in the upper region of the apparatus, rings lid and Bl cannot roll down planes 49 and die into contact with flat portions 48 and 43a of the driving and driven runners respectively. Accordingly rings 54 and 6l' engage each other under considerable pressure and are slightly deformed (Figure 6), and they react'against the driving and driven runners with considerable force. Centrifugal force is accordingly utilized to seal the device against the escape of abrasive on the closedv Y side of the apparatus. Rings hd and lill, in moviii .Eil

ing from the positions they assume on the closed side of the device into the positions they assume on the open side of the device, roll down inclines it and 49a under the influence of centrifugal force and undergo a torsional or longitudinal deflection or twist. This action also occurs when rings lland B1 are rolled up inclines 49 and lita against the action of centrifugal force from the positions they assume on the open side to the positions they assume onthe closed side of the runners. f

As these occur each cycle, or once every revolution of the runners, it is apparent that the rings must be of a material that possesses sucient resilience to stand this action. I have found that comparatively soft rubber rings are admirably suited for this purpose, although it is to be understood that if desired, other materials may be used in the device without departing from the spirit of my invention.

It should also be observed that as rings 54 and |51 move from their retracted or closed positioninto their extended or open position, they undergo a purely rolling action on planes 49 and 49a, with the result that substantially no friction is involved and substantially no heat is developed in the rings and they accordingly have a long life.

, As a matter of fact, centrifugal force is so great that it causes portions ofthe rubber rings to be deflected slightly downwardly into circumferential grooves 5| with the result that they c'ooperate therewith to form in effect racks and pinions, to insure against slippage during operation. Accordingly, if desired, rings 5d and 61 may be provided with corrugations to fit into grooves El and insure rolling movement thereof, as distinguished from a sliding action.

With rference to the lupper portion of Figure 6, which illustrates the closed side of the runner assembly, it is observed with the machine running that rngs 54 and 6l, under the influence of `centrifugal force cooperate to define a toggle joint having arms |35 and |36. Arm |36 applies what may be termed an active force to portion 49 of driving runner 33 and arm |36 applies what may be termed a reactive force to portions 49a of driven runner 51. These forces result in urging driven runner 51 to the right against the ac. tion of spring i2'l when the machine is started and attains normal running speed, and it is this force that holds the bearing assembly with boss N39 spaced from ratchet member lili with the running clearance designated as itl therebetween. It is apparent that should the machine be stopped, the centrifugal forces acting on rings td' and ull will drop to zero and spring itl will move the driven runner to the left, thereby compressing rings 54 and 6l and taking up clearance i311. By reason `of boss |09 engaging ratchet member illi, the rings are relieved of the Afull pressure of spring |21 when y,the machine is not As previously indicated, it is highly desirable that a predetermined pressure be exerted upon rings 54 and $1 in order to predetermine the proper operation of the mechanism, and to this end nut lit is preferably adjusted on screw Ilii at the factory, or the parts (nut lit and screw iii) marired so as to place spring lil under a predetermined compression. When the machine leaves the factory and has been placed in use the runners are brought up to normal operating speed, latch |211 is liftedv and screw iii is turned so as to bring hair lines H8 and l iii into registry. This assures that the parts will be placed under the proper pressure and that proper operation of the machine will ensue.

Assuming now that the machine is operating lat normal running speed (2400 R. P. M.) and that the desired types of abrasive (metal grits, sand, etc.) are introduced into funnel itt, when the abrasives initially strike sleeve ti they are picked up from a substantially stationary condition, rotatably speaking, but as the surface of member t3 is fairly close to the axis of revolution of the driven runner, the surface which the abrasive strikes is not rotating at an excessive peripheral speed, and therefore the abrasives are picked up with a minimum of wear to this part. Rotation of the various elements sets up an air current which produces a suction in the driven runner and the incoming air-stream assists feeding the abrasive to the left. As the abrasive moves to the left from sleeve 63 it is gradually accelerated, and as wall t2 is of gradually increasing diameter the abrasives are further accelerated as they move to thevleft. As the abrasives pass over the left hand end of Wall 62 they drop into the distributor plate assembly wherein they are gradually accelerated as they drop from ledge to ledge in the manner previously described. When the abrasives are finally deposited upon the closed side of the ring, which in this instance is the upper part of the apparatus, they form a substantially stationary deposit between the crotch of rings 54 and El, as indicated in Figures 3 and 6. The depth of the deposit, and hence the volume of abrasive discharged, will depend upon the quantity of abrasive supplied the machine. A layer of abrasive which is substantiallysta-r tionary with respect to the peripheral velocity of rings 54 and 61 is accordingly deposited upon the latter, and when the rings reach the open side of dll the machine and spread apart, the layer of abraadjusted however by inserting shims 9| between or withdrawing the shims from between support 88 and cover I6 in order to increase or decrease the angle 58.

adjusted so as to decrease angle 58 whereas if it is desired to increase the width of the abrasive blast, angle 58 is increased.

Abrasive is therefore continuously passed through the machine, and it is observed that although the major part of the abrasive issuing therefrom has previously been depositedin the crotch of the rings, a certain amount of abrasive drops directly from tortuous passage 4| into the open discharge gap. As the runners recede from the open side position, it is apparent that as the rings contact and close the opening, and as the runners approach each other, rings 54 and 61 will contact each other and roll up inclines 49 and 49a respectively against the action of centrifugal force and the pressure set up between the rings effectively seals them against abrasive leakage.

It is therefore observed that the rings are continually rolled around circumferentially in the grooves in the respective runners, and in effect undergo a tilt every revolution, and this tends to cause an air current to travel circularly in the grooves in a direction opposite to the direction of rotation of the runners. This air current might interfere with proper opening and closing movements of the rings if grooves 44 and 56 were entirely closed, and I have therefore provided apertures 53 and 53a at spaced points in the driving and. driven runners respectively in order to establish atmospheric communication with the grooves and allow air to freely enter and be exhausted therefrom in response to the pulsating action of the rings therein. 'Ihis prevents a vacuum from. being established lbehind the rings and also provides effective Ventilating currents. A rod may also be inserted through apertures 53 for removing and replacing rings 54 and G1.

In view of the fact that the terminus of tortuous passage 4| is disposed opposite the meeting faces of rings 54 and 61, most of the abrasive is deposited upon the latter; However, some abrasive may get behind rings 54 and 61, and this abrasive works downwardly into circumferential grooves 5| and it is centrifugally drained from these grooves by intersecting drain holes 52 and 52a associated therewith.- It is therefore seen that rings 54 and 51 are assured of a clean surface upon which to roll, with the result that their rolling action does not abrade them in the least.

The centrifugal fan effect produced by the skin friction of the various rotating parts has previously been described as useful in feeding the abrasive into the device. These air currents are also very beneficial from the standpoint of ventilation, as they ow over all the parts and maintain the temperature at a safe value. The heated air is adapted to be exhausted at the open side of the apparatus and also through a plurality of exhaustports 64 provided in the driven runner. If desired similar ports may be provided in the driving runner.

'Ihis machine may be used in various relation- If it is desired todecrease the width Y Vof the abrasive blast or stream, support 88 is ldesired cleaning or blasting operations. In order to prevent articles from coming into contact with the rotating head and to also prevent extraneous abrasives from being discharged at random into the air, I preferably provide the apparatus with a guard which comprises segmental shield members |4| and |42 which are secured to the lower face of base A in any suitable manner, Shield |42 is provided with a partition |43 and a baille plate |44 having a perforation |45 in its lower region. As abrasive gravitates through an opening |46 formed in base A it is guided by baille |44 to perforations |45. As the abrasive finds its way through perforations |45 it drops into shield |42 and gravitates outwardly of the apparatus by way of an opening |41 in partition |43. Abrasive thrown from any of the rotating parts which might ricochet upwardly through passage |41 in partition |43 and then into the bearings is arrested by the unperforated portion of baille |44.

After the machine has been in use for some time rings 54 and 61 will wear to some extent, but spring |21, acting upon the driven runner in the manner previously described, causes the driven runner to move toward the driving runner and compensate for this wear. When the rings have become worn to a greater extent, boss Il! will move into contact with ratchet member and at this time is preferable to restore the original spring pressure. This is preferably effected by lifting latch |2|, and turning screw inwardly by means of squared portion |3| to bring hair lines ||8 and ||9 into alignment. Operating screw in this manner causes the entire assembly to be pulled to the left because this action threads screw into or toward support 88. When the hair lines have been brought into registry, latch |2| is dropped into place. This operation is effected while the machine is operating and it accurately restores the original spring pressure with which the machine was originally put into operation, for the reason that it restores the original relationship of spring |21 and sleeve 11 and thereby puts rings 54 and 51 under the originalI pressure.

As previously described, nut |29 is turned up to a predetermined point on screw I at the factory and that thereafter all adjustments to compensate for wear are effected by screw Il. If desired, this procedure may be omitted and the machine calibrated by adjusting nut |29 after the machine is started. Thisoperation is effected in the following manner. bled-and nut |29 is taken up to a. certain extent to place some pressure upon spring |21. The machine is then started and abrasive is supplied thereto. Screw is then rotated to bring hair lines ||8 and 9 into alignment and latch |2| is. dropped in place to lock screw Hl against turning movement. The character of the blast stream issuing from the machine is then carefully observed and nut |25 is turned in the proper direction to bring about the proper blast stream. While this adjustment is being effected, the changes in the spring pressure may be sufficient to cause boss |09 to move to the left or right and bring hair lines ||8 and ||9 out of registry, and if this occurs, the screw should be adjusted to bring them into registry before the final adjustment is given nut |29. When the blast stream assumes a proper configuration, nut |29 The parts are assemis then locked in place in any suitable manner (not shown) and the machine is operated as previously described. Thereafter, upon wear of rings 54 and 6l, screw III is manipulated in the manner previously described in order to compensate for wear of the rubber rings, and nut |29 is left undisturbed as it has been previously calibrated to give the., desired spring pressure with hair lines H8 and I i9 in registry.

'When rings 5t and ii'l have become so worn as i to be unt for further service, the machine is.

disassembled and the rings replaced in the following manner. Nut H9 is backed off to relieve the driven runner of pressure and the whole assembly is moved to the right (Figure 3) to bring hub portion 5d of the driven runner out of engagement with the opening in distributor plate dt. Nut 2l is then loosened and stud it is swung outwardly about its pivot to bring it clear -of ears 2d of cover i6. Handle 2u is then grasped and the whole assembly lifted upwardly about pin 2t as an axis. It is apparent that with cover it raised in this manner, both the driving and the driven runners are exposed throughout 360 of their area and the rings as well as distributor plates l5 and 36 may be replaced and any other part inspected.

With the cover I6 raised in this manner, a screw driver or the like is inserted in the grooves ben hind rings 5d and lil andthe latter removed therefrom. Two new rings are then inserted in the grooves and although the edges of the groove lila are smaller than the diameter oi the rings, the latter are soft and pliable and may be readily worked into place by inserting a portion thereof in the groove and then working progressively around the ringto get the entire ring into position in the groove. After the rims have been replaced in the manner just described, cover lli ls lowered into place, the driven runner is then shoved forwardly to bring the rings into contact with each other at .the closed side of the apparatus and nut l2!) is screwed in place on screw l l l. The machine then may be placed in operation and adjusted and calibrated in the manner previously set forth.

Although I have illustrated a device employing rings that are axially movable with respect to the driving and driven runners, and l prefer to employ this arrangement, as it possesses the advantages pointed out in detail, it is to be understood that if desired they maybe omitted and one or both of the runners provided with a soft or yielding edge so fas to seal the device against abrasive discharge on the closed side ofthe device, and the appended claims are intended to embrace my apparatus when lt assumes this form. Moreover, as my invention in its broadest aspectsl comprises a rotatable mechanism adapted to receive abrasive and having means for discharging the abrasive from the wheel as it progressively reaches a predetermined point, the rubber rings illustrated, which constitute an infinite number of valves, may be substituted by a plurality of valves of any other description, such as mechanical valves having a mechanism for tripping them each revolution of the runners, Without departing from the spirit of my invention.

It is to be particularly observed that in the present ,instance the axes of the driving and driven runners intersect at a point that is substantially radially opposite the Acontacting portions of 'the two rubber rings, in order that the runners will run true. In other wor-ds, if the runners were eccentrically mounted, the4 rubber rings on the closed side of the assembly would in their respective grooves by reason of the eccentric character oI the two runners. VHowever,

a slight rolling or weaving action of this character is not harmful and therefore it is only necessary to secure approximate alignment of the driving and driven runners.

With reference to Figure 2, it is observed that cap screws 89 pass through elongated slots 90 in supports t8 with the result that cap screws B9 may be loosened and the entire support rocked slightly clockwise or anti-clockwise to direct the abrasive discharge at different angles. If desired, the entire machine may be mounted in a cradle or the like for rocking movement about the axis of shaft i4 so that the abrasive blast may be directed at any desired angle. Moreover, the machine may be mounted for rotation in a cradle orthe like about the axis of shaft it and be driven by a slow speed gear arrangement or the like for causing the blast to travel through 360 for cleaning the interior of cylindrical bodies or the like.

With reference now to Figure 7 of the drawings, l have shown a modified form of ring assembly, associated with the runner assembly shown in Figures 1 to 6, inclusive. With continued reference to this figure, distributor plate 3E is provided with an outwardly extending flange ibi. Driven runner 5l isprovided with a similar flange ld. Rubber rings 5ta and Ela, which are disposed in grooves M and 66, are provided with circumferential lips or flanges E53 and ilill resctively, which cooperate with flanges itl and This form of my invention functions in precisely the same manner as that just described, as rings tile and Ela are free to roll up and down the inclined portions t@ and ltd of the driving and driven runners, but in this instance it is observed that as lips E53 and l5@ contact flanges 4liti and l52 when the rings roll toward each other, the rings are definitely stopped in predetermined positions, and it is not necessary to give inclined portions 43 and i811 of the runners as steep a pitch, because they do not constitute the sole limiting means for the rings, as do the corresponding portions in the rst form of my invention.

When it is desired to replace the rings, the operation is carried out in exactly the same manner as that described in connection with the rst form of my invention and when the newrings are inserted in the grooves, the lips itl and ld are inserted rst and eachcring is pushed into place and progressively inserted throughout the circular extent of therunner.

With reference now to Figures 8 and 9 of the drawings, I have illustrated a further modified form of ring assembly, and in this form of the invention the distributor plates ,are also of a slightly modied construction.

`With continued reference to these figures, distributor plate 35a is connected to distributor plate 36a in a manner similar to that shown in the device of Figures l to 6, and the outer edge of plate 35a is provided with a plurality of fins ll which are staggered with respect to a plurality of similar ns 162 formed on distributor plate 36a. iributor plate 35a is also provided with a plurality of radially extending passages H53 and plate 36a is provided with a plurality of similar passages l64. The passages and fins just described serve to distribute the abrasive over a wider area than the distributor plate arrangement used in Dis dit

the first form of my invention for the purpose of spreading it over the wide ring arrangement used in this device and which will now be described.

Driving runner 33a isprovided with an annular groove 44a which is provided with a substantially cylindrical outer surface |66, with the result that ring 54a does not tend to undergo axial movement in response to .centrifugal force. Groove 66a of driven runner 51a and which contains ring 61a is constructed in a similar manner to have a cylindrical outer wall |61. However, if desired the outer walls of groove 44a and 66a may be inclined so as to enable rings 54a and 61a to respond to centrifugal force and augment their ring compressing action.

Disposed between rings 54a and 61a is the preferably integrally formed rubber ring |68 of cylindrical shape and it is held therein by the outer wall of grooves 44a and 66a and at its inner edges is guided by lips |10 and 1| formed on the driving and driven runners respectively. Ring |68 is provided with a plurality of circumferentially spaced slits |12 having beveled upper edges |13. The central portion of ring |68 is preferably provided with a plurality of reinforcing members |15, which may be of cord or wire, and which are integrally molded in the rubber. Reinforcing members |15 function to prevent the central portion of the rubber ring from bellying out in response to centrifugal force.

The operation of this device is somewhat similar to the forms of my invention previously described and assuming that when the wheel is operating at normal running speed, screw is adjustedso that the upper side of the wheel, by reason of the axial difference of the driving and driven runners, will be closed. Closing slits |12 in this device is effected by driving and driven runners acting through rings 54a and 61a which deform the cylindrical ring |68 and force the walls of the slits into tight sealing engagement.

When the machine is adjusted to give proper tension the operation is as follows. Abrasive trickles outwardly through tortuous passage 4| and then passes between blades |6| and |62 into passages |63 and |64 of the distributor plates where it is deposited upon the tapered beveled faces |13 of the slits |12. As the runner assembly rotates into open or discharging position, slits |12 open up, through the inherent resilience of the rubber, and allow the deposited layer of abrasive to be centrifugally discharged therethrough. When elements |66 wear in response to normal use, the pressure on the driven runner is increased by adjusting screw as previously described in connection with the first forms of my invention- When it is desired to replace member |68 the machine is disassembled and the parts replaced in the manner as that previously described.

Although I have illustrated and prefer to employ a pair of rubber rings 54a and 61a to compress cylindrical ring |66 and close the openings therein, they may be omitted if desired and ring |66 be allowed to extend the full width of the device and into the groove in the respective runners. Moreover rings 54a and 61a may be augmented or substituted by a resilient means of any other desired character, for instance a circular leaf spring or the like.

With reference now to Figure 10 of the drawings, I have illustrated a further modified form of abrading apparatus which is somewhat similar to that just described. In this form of the invention driving and driven runners 33h and 51h are provided with grooves 44h and 66h which are adapted to receive the outermost pair of three separate rings |8|A of prefeblyf'identical construction. Each ring |8| is'made up of a rubber body portion |82 and a, steel reinforcing ring |83 which is T-shaped in cross-section and which controls the action of the rubber under the iniiuence of centrifugal force. Each ring |8| is provided with a beveled portion |84 so as to define V-shaped abrasive receiving grooves when they are disposed on the closed side` of the apparatus.

Distributor plates 3517 and 36h are secured to driving runner 33h in a manner similar lo that disclosed in the previous forms of my invention, but the outer periphery of plate 35h is provided with a plurality of teeth or blade members |85. The outer peripheries of teeth |85 are turned to provide substantially true cylindrical surfaces |86 upon which central ring member |8| is mounted. Distributor plate 36h is provided with a plurality of teeth |61 which interengage with teeth |85 of plate 35b. As seen in Figure 10 teeth |85 and |81 provide a plurality of passages through which abrasives may pass fromv tortuous passage 4| to the spaces between the three rings.

The operation of this form of my invention is somewhat similar to that previously described. When the runners have been brought up to speed abrasive is fed to the device and as it passes through the spaces between the interengaging teeth it will be guided into the V-shaped receptacles defined by the inner edges of rings |8|, upon which it is deposited.

Spring |21 is placed under the requisite degree of compression to insure that the sealing engagement of rings |8| will prevent abrasive leakage from the portions of the ring on the closed side of the apparatus. When the runners attain open side position, the pressure is relieved from them, and spaces will develop therebetween, as illustrated in the lower part of Figure 10, and the abrasive previously deposited upon them is then centrifugally discharged from the apparatus. It is observed that the steel reinforcing members |83 are so related to the ring that they are not subjected to the action of the abrasive, with the result that when the rings are removed and replaced, the old rings may be remolded and used over again by employing the original reinforcing elements as the foundation for new rings.

With reference now to Figure 11 of the drawings, driving runner 33c and driven runner 51e are mounted for rotation in precisely the same manner as the driving and driven runners of the previously described apparatus. In this form of the invention the distributor plates are substituted by a funnel shaped member |9|, which is secured to the driven runner in any suitable manner as for instance by means of cap screws |92. Member |9| operates as an-abraslve distributing and accelerating member and flares outwardly and terminates adjacent an annular groove |93 formed in a removable cylindrical Wear-,ring |94. Member |94 is provided with a flaring apron portion |95, which is provided with a plurality of apertures |96 through which the abrasive is adapted to be fed to the rings.

The ring assemblies shown and described in connection with the modifications of the invention illustrated in Figures 8. 9 and 10, may be used in this device, but I preferably employ a plurality of rubber rings |98, which have cords |99 molded therein for the lpurpose of reinforcing them against distortion in response' to centrifugal force. Rings |98 seat\ in grooves c and 66e provided in the driving and driven runners 33e and 51e respectively. The outer rings |98 are also guided by means of rings 20| and 202 which are secured to the driving and driven runners respectively. v The driven runner is also provided with Ventilating holes 65, and apron|95 has ring centering ribs 200. v Y Basically, the operation of this device is similar to that of those previously described, and when the'machine has been brought up to speed and spring |21 has been placed under svufcient compression so as to force rings |98 into proper sealing engagement on the closed side of the device, the abrasive is admitted to the machine. The abrasive is gradually accelerated by walls '62e of the driven runner and it spreads outwardly over the inner surface of member |9| where it receives a further accelerationand is spread out so that it is uniformly deposited in groove |93 of member |94. As indicated in Figure 11, groove |93 always contains a substantial quantity of abrasive, with the result that the bottom of the groove is never subjected to the direct abrading action of the abrasive leaving member I9|. The abrasive overows from groove |93 onto apron |95, Where it is evenly distributed and finds its way through openings |93 to the inner sides of the rings. A part of the abrasive travels past openings |96 and is deposited upon the right-hand' pair of rings of the device. When the rings attain the open side of the device pressure is relieved from them and they spread apart and ,allow the layers of abrasive deposited thereon to f .be'centrii'ugally discharged from the device. As

the adjusting and part replacing v4operations of theconstruction are identical to those of the' prevviously described mechanisms they will not be further set forth.A

In Figure`12 of the drawings I have illustrated a modified form of abrasive ring assembly which may be employed in all of the illustrated constructions except that shown in Figure 1, and it consists of a metallic ring 2M which is substantially H-shaped in cross section. Frictionally v disposed or vulcanized in place in each of the grooves formed in the opposite sides of each ring 204 is a rubber ring 205 whichV is adapted to rictionally cooperate with the rubber ring of an adjacent ring assembly. These rings function Vsubstantially in the same manner as thosepreviouslysdescribed as the rubber elements thereof undergo compression when the rings are compressed on the closed side of the apparatus and, when they are on the closed side of the device, they define a plurality of annular depressions into which the abrasive is deposited.

At this point a brief comparison of the characters of the abrasive streams issuing'from the respective machines illustrated will be set forth. With reference to the machines shown in Figures 1 to 'I inclusive, the opening on the open side of the machine assumes the formjof a slit having tapered ends. The abrasive dischargedfrom the v leading edge of the slit has, up to the time of discharge, been resting in a substantially stationary condition upon the rings, ,with the result that it is discharged in a substantially tangential direction but in restricted volume by reason of the restricted area of this part of the' slit. The abrasive 'issuing from the central and trailing portions of the opening takes a different direction, as seen in Figure 2, for the reason that a part of this abrasive is thrown directly from the A instance by providing side of the driven runner manner, and with reference to the device shown in` figures 8 and 9, wherein a single slitted ring is employed, it is apparent that as the slits pass through the opening cycle, they will initially open to a slight extent, so as to discharge' a part of the abrasive deposit thereon ina tangential direction, and will then: open to their fullest extent to discharge the remainder of the abrasive `deposit and also abrasive throwntdirectly from the distributor plate assembly. The slits will then close and cause a fresh abrasivev deposit to be built up thereupon for discharge during the next cycle of operation.

It is therefore apparent that the abrasive stream discharged from all of my machines. is substantially uniform throughout Y- its width, as distinguished from the non-uniform discharge of prior paddle wheel machines.

In connection with all of the forms of my invention disclosed herein, it is to be observed thatA althoghl have illustrated and preferred to journal the driven runner in bearings, so as to maintain it in a denite position, if desired, the bearings for the driven runner may be omitted and the' latter carried directly by the driving runner without departing from the spirit of -my invention.l For instance, with reference to Figure 1,

and Figure 3, driving studs may be securedto' driving runner 33 and extend through apertures in the rear wall of driven runner 51 to provide a driving connection, and compression springs may encircle studs and bear against the .rear face of the driven runner and against the heads of nuts threaded on the studs. These spring assemblies will provide adrivi ng Vconnection between the driving and driven runners and at the same time will urge them toward each other vso as to place the rubber elements under compression on Vthe closed side of the machine. The driven runner may be tilted in this device, so as to provide a discharge point, in any suitable manner, as for the driven runner with a raceway and associating therewithla stationary supported, axially adjustabley roller to urgepne to left av slight distance to predetermine the discharge-point.

In the device just described; rollers may be mounted for axial movement, in order to provide` for adjustment of the size of the discharge opening, and the spring pressure may be adjusted by tightening or loosening the nuts on the studs. If desired, however, 'the arrangement of the parts of this device may be reversed, and the springs .be employed tourge the runners away from each other and the roller may be located at the closed side, and operate under the action of an adjustable spring to force the driven runner toward the driving runner. Any suitable means may be eln- A ployed to prevent the driving and driven runners my invention when it assumes this form. Moreover, I have shown a device wherein the ,shims 9| may be removed or inserted between the parts so as to vary the axial difference between the driving and driven runners, but it is to be understood that if desired any other suitable form of mechanism for selectively adjusting the position ofthe driven runner with respect tothe driving runner may be employed without departing from the spirit of my invention. For instance, an eccentric sleeve may be employed to support the sleeve member '11, and be so vdesigned that rocking movements of the eccentric sleeve will cause the' angle 58 to increase or decrease to any predetermined value. Moreover such eccentric sleeve may be rocked by a power means and synchronized with the operation of the apparatus with which the machine is used so as to produce a varying abrading action, i. e. a stream of uctuating width, or any other action, in any suitable manner. It is also to be understood that the eccentric device just mentioned may be employed to bring driving and driven runners into alignment with the result that when they are forced together they will close the abrasive chamber dened by the head throughout 360 of their circuniference to positively shut olf the abrasive stream. On the other hand, should the runners be separated a slight amount while their axes are in alignment the machine will discharge the abrasive through 360 of their circumferences which may be used to advantage in certain abrading operations.

Although I have illustrated in Figures 10, 11 and 12 oi' the drawings, a device using a plurality of rings, which gives a comparatively wide blast stream, it is to be understood that if desired for the machines to give a narrow stream, one or all of the intermediate rings may be omitted to thereby give a blast having a narrower abrasive stream. Moreover, the two rings which are associated with the driving and driven runners respectlvely in such device may be of hollow construction and inflated to a predetermined pressure to enhance the sealing action thereof when they are pressed together, and it is to be understood that the appended claims are intended to embrace my invention when it is embodied in this form.

I have found as a result of experiment that the pressure which must be exertedby spring |21 upon the driven runner when the machine is operating lies in the neighborhood of 800 pounds for the machine illustrated in Figures 1 to 7 of thevdrawings, and that'for the machine illustrated in Figures 8 to 12 inclusive, the pressure lies in the neighborhood of 2000 pounds. It is to be understood, however, that these pressures and also the speed at which the machine must be driven will depend upon the size of the wheel. For instance, if a, larger wheel is used, the speed may be reduced, because of the greater radius from which the abrasive is thrown, and the spring pressure willI creased.

Although I have illustrated, and prefer to employ a spring assembly for applying pressure to the driven yrunner, it is to be understood that if desired a hydraulically or pneumatically operated piston and cylinder assembly may be employed to urge the parts together, utilizing a source of hydraulic or air pressure having a constant value in order that the parts will be urged together under a predetermined force at all times.

probably have to be in as wear of the rubber elements takes place. This obviates the necessity for adjusting screws or nuts. If desired the air or fluid pump may be driven synchronously with or controlled synchronously by the operation of driving shaft I4 in order to automatically relieve the rubber rings of pressure when the machine is stopped. If desired a iluctuating pressure source may be used and a pressure regulator interposed between the Source and the cylinder. As most pressure regulators are adjustable, it is apparent that with this assembly the pressure with which the rubber ring is gripped between the runners may be accurately adjusted. A valve may also be provided to instantly relieve the runners of pressure.

.In Figure 13 I have illustrated one for'm of mechanism that may be used in lieu of the spring organization shown in Figure 4. In this form of my invention, boss |09a is provided with a at rear face, to which is secured, by means of cap screws 209, a piston rod sealing assembly 2I0 and a cylinder head 2| I. Secured to head 2I| by bolt and nut assemblies, and having a gasket clamped therebetween, is a. cylinder 2I2 having an apertured end 2I3.

Screw I I Ia, which is of slightly modified form, extends loosely through boss |09 and into cylinder 2I2. Secured to screw IIIa, by means of a nut 2I4, is a piston assembly 2 I5. Screw II Ia accordingly functions as a piston rod, ,but as it is carried by stationary support 88 its position is xed, while the cylinder, which is connected to sleeve TI, is adapted to undergo movement in response to uid pressure.

Communicating with cylinder 2|2, by means of a fitting 2I1, is a pipe 2|8, which is connected to the low pressure side of a`pressure regulator 2I9. Pressure regulator 2|9- may be of any desired conventional form, and is preferably equipped with an adjusting screw 22|', which may be manipulated to increase or decrease the regulator spring pressure to thereby increase or decrease the-air pressure delivered to pipe 2|8, in well known manner.v Air may be supplied to the high pressure side of the regulator from a compressed-air source, whose minimum pressure is in excess of the low pressure side, by any suitable means, such as a :flexible hose 222, and a valve 223 is preferably inserted in line 2|8 for controlling the air supply to the cylinder. Valve 223 is so designed that when handle 224 thereof is disposed inits full line position, the cylirbder will be in fluid communication with the regulator, and when disposed in its dotted line will be in fluid communication with the atmosphere.

The machine may be placed in operation as described in connection with the firstrforms of my invention, and control valve handle 224 is preferably rocked into its full line position simultaneously with, or prior to starting the runner, so that the driving and driven runners will be disposed in driving engagement when the machine is brought up to speed. I f desired this coordination of operation may be attained by connecting valve handle 224 to the starting mechanism of the prime mover, or mechanism responsive to the speed of the driving runner may be used to control th'e valve.

When air pressure is admitted to cylinder 2I2,

. it is apparent that it will react against piston 2|5 position the cylinder and act against cylinder head 2II to cause the latter to move totheleft and bring the driven runner intofrictional engagement with the driving runner. If desired, particularlyv when this assembly is used with the machine shown ln Figure 1, a nut 225 may be adjustably threaded onto screw IIlla to limitthe movement of boss |09a and the relatedA parts under the influence of air pressure, so that when the runners are stopped, or are being started, the air pressure `will not compress the rings and bring the runners into actual contact. If, however, operation of the valve is coordinated with operation of the starting mechanism, as above-described, nut 225 may be omitted and a restriction placed in pipe H8,

so as to retard air flow into cylinder 2I2, to thereby delay attainment of full pressure until the runners have been brought up to normal running speed.

With the machine running, and with Athe air control valve open, the parts assume the position shown in Figure 13, and it is apparent that the runners are urged together under a predetermined pressure. When the machine is initial-ly` placed in service, screw 22| is adjusted to establish proper pressure conditions, and this adjust- Vment is preferably made with the machine in operation, as the blast stream can then be observed and screw 22| adjusted accordingly. After this adjustment has been made the setting thereafter need not be disturbed, unless other adjustments are made that would require an increase or decrease in pressure (for instance, installing different type rubber rings,'changing angle 58, etc.)

It is therefore seen that the pneumatic `cylinder exerts a constant pressure upon the driven runner at alltimes, with theresult that'although the rubber ringswill wear in service, and the driven runner will move to 'the left under the iniluence -of the cylinder assembly, and compensate for the wear, the pressure will nevertheless remain con- T stant, and the apparatus is therefore self-adjusting for wear.

The piston' and cylinder area and the pressure regulator delivery pressure are. preferably designed sov that a pressure of approximately eight hundred pounds is exerted when the pneumatic control is used in the first form of my invention,.

and a pressure 'of approximately two thousand pounds is exerted` when it is used in the other forms of my invention. If desired, however, the pressure regulator may be omitted if a source of substantially constant air pressure is available.

Although- I have'v illustrated and prefer to employ a pneumatically operated device, because air is elastic and urges the runners together with a yielding pressure, .itis to be understood that the I` cylinder assembly maybe energized by oil or other liquids or gases, without departing from the spirit of my invention, and theterm iiuid, as employed in the appended claims, is therefore intended to embrace these energizing media.

vils previously explained, the parts`are illustrated in Figure 13 as they appear when the machine is operating at normal speed, and it is .seen that a considerable clearance exists between cylinder head 2l l and the piston assembly. This is stopped with the air pressure c ut off, andit is desired to lift the lcover and replace the rings'l the'driven runner assembly maybe readily slid rearwardly to clear the other parts and the cover '"lifted." In this connection, I preferably mount the pressure regulator upon boss Ia or the cover, so that it will lift upwardly as a unit with the cover. 0f course, if the regulator is mountedl on the cover, pipe H8 will be of a flexible-char- Iacter, so as to permit the driven assembly to move toward and away therefrom.

In most installations where apparatus of the character disclosed herein are used, compressed air is usually available and supply pipe 222 may accordingly be connected thereto. However, if a compressed air source is not available, pipe 222 may be connected to a suitable pump, preferably driven by driving shaft or by the motor thereof so that pressure willautomatically build up in v l to 'I inclusive and l0, l1 and 12, frictional engagement of the rubber ringsis operable to seal the head, defined by the runners against abrasive discharge on the closed side of the machine and is also effective to effect a. driving connection between the runners. In the device shown in Figures 8 and 9, a single slitted ring is used and although frictional engagement of the walls of the slits on the closed side of the device seal the head against abrasive discharge, such frictional engagement plays only a minor part 'in establishing a driving connection between the runners, be-` cause of the bodies of rubber disposed directly therebetween. It is therefgore apparent in all of the forms of my invention the head is sealed against abrasive discharge on the closed side of the machine by frictional engagement oi the rubber, and the term frictional engagement employed in the appended claims is therefore intended to cover this feature irrespective of.

whether the driving and driven runners are frictionally or mechanically connected together for synchronous rotation or are each driven by an individual prime mover.

I have shown the driven run'ner as being journaled independently of the driving runner, and I I prefer to employ this arrangement, but it is to be understood that if desired one end of thev driven runner vmay be journaled upon the driving embodiment is therefore to be considered in all,

respects as illustrative and.not restrictive, the" scope of the invention being indicated by the appended claims rather than by the `:foregoing description, and all changes which come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein.

What is claimed and desired to be secured by United .States Letters Patent is:

1. An abrasive propelling device comprising a pair of members mounted for independent rotation, said lmembers being disposed with their u axes inclined at an obtuse angle to each other, means disposed between said members and cooperating therewith to seal said members against abrasive How therebetween throughout a portion of each revolution, and to allow abrasive to flow therebetween throughout another portion of each revolution, and means for feeding abrasive between said members adjacent the axes thereof.

2. The device described in claim 1, wherein said means comprises at least one annular flexible element frictionally gripped between said members.

3. An abrasive propelling device comprising a rotatable member having substantially circularly disposed, axially facing sealing faces, a second member adapted to rotate synchronously with said first member and also having substantially circularly disposed, axially facing sealing faces, and means for causing said members to rotate with a portion of their sealing faces in 4engagement, and means for feeding abrasive between said members.

4. The device described in claim 3, wherein said means comprises means for causing one of said members to tilt with respect to the other member. v

5. The device described in claim 3, wherein the sealing faces of said first and second members are provided in an element which is frictionaily gripped between said members.

6. An abrasive propelling apparatus comprising at least two members mounted for synchronous rotation and having at least one resilient element disposed therebetween, said members being disposed with their axes inclined at an angle of somewhat less than 180 to each other, said members and element defining an abrasive chamber, means for introducing abrasive into said chamber, and means for causing said resilient element to seal said members against abrasive egress during one portion of each revolution of said members, and to automatically provide at least one opening and allow abrasive to be discharged from said chamber during another portion of each revolution of said members.

7. The device described in claim 6, together -with resilient means for urging said members to centrifugal force when said members are` rotated, and means for urging said members toward each other against the action of the forces developed in said flexible element, said flexible element operating to seal said members against abrasive flow therebetween throughout a portion of each revolution, and to allow abrasive to flow therebetween throughout another portion of each revolution, and means for feeding abrasive between said members.

9. The device described in claim 8, wherein said means is resilient and is selectively operable to apply forces of varying magnitude to said members.

10. For use in an abrading apparatus havingV at least one rotatable runner from the periphery of which abrasive is centrifugally discharged, a.

pair of abrasive distributing members adapted for synchronous rotation with said runner and operable to feed abrasive from a region adjacent the axis of said runner to the periphery thereof, said distributing members being of generally circular shape and having their facing surfaces so formed as to dene a tortuous passage.

11. An abrasive propelling apparatus comprising at least two members mounted for synchronous rotation and having at least one resilient element disposed therebetween, said members and element defining an abrasive chamber, means for introducing abrasive into said chamber, and means for causing said resilient element to seal said chamber against abrasive egresslduring one portion of each revolution of said members, and. to automatically provide at least one opening and allow abrasive to be discharged from y said chamber during another portion of each revolution of said members, and means, providing a resilient air cushion, for urging said members toward each other.

12. 'I'he apparatus described in claim 11, wherein said members are mounted for relative axial movement, and said air cushion is operable to exert a force of constantmagnitude upon said members, irrespective of their relative axial positions.

13. An abrasive propelling device comprising a pair of members mounted for synchronous rota.- tion and adapted to define an abrasive chamber, a resilient deformable element frictionally gripped between said members and having a plurality of openings therein, and means for feeding abrasive to said chamber, said members being mounted for rotation about non-parallel axes, to thereby cause one portion of said element to be gripped and another portion of said element to be substantially uncompressed, to thereby cause the openings vin said portions `to be respectively closed and open\for controlling discharge of Y abrasive from said chamber.

14. An abrasive propelling device comprising a pair of disc-like members mounted for synchronous rotation closely adjacent each other about non-parallel axes, each of said members having a groove in its periphery, the walls of each of said grooves inclining outwardly and toward the other member, a resilient element disposed in each of said grooves and cooperating with said members to define an abrasive chamber, means for feeding abrasive to said chamber, said elements being responsive to'centrifugal force to roll upon said inclined walls and to engage each other and seal one side of said chamber.

15. The abrasive propelling device described in claim 14, whereinv each of said grooves is provided with a second inclined wall for limiting movement of said elements toward each other under the influence of centrifugal force.

16. An abrasive propelling device comprising at least two members mounted for synchronous rotation closely adjacent each other about nonparallel axes, said members cooperating to define an abrasive receiving chamber, means for feeding abrasive to said chamber, and resilient means disposed between said members and operable to maintain one side of said chamber closed at all times and another side of said chamber open at all times, and means for gradually accelerating the abrasive fed to said chamber up to the peripheral speed of said resilient means as the abrasive moves outwardly in response to censtructure rotatableat high speed, said structure providing a plurality of annular abrasive slipporting surfaces disposed circularly around said structure and said surfaces facing inwardly toward theaxis of rotation of said structure, means for feeding abrasive to the interior of said vstructure and for depositing it upon said surfaces, and

abrasive controlling means for causing each of said surfaces to retain abrasive thereon during a portion of each revolution thereof, and for causing the abrasive accumulated thereon to be discharged therefrom during another portion of each revolution. y o

18. An abrasive propelling device comprising a rotatable member, means for introducing abrasive into said member, andY means cooperating with said member for preventing said abrasive from escaping from said member while Vthe latter is rotating through a predetermined angular part of each revolution, said member being operable to propel said i, abrasive at abrading velocities when said member is rotated through another lfacing toward the axis of rotation of said structure, means for feeding abrasive to the interior of said structure and for depositing it upon said surfaces, and abrasive controlling means for causing each of said surfaces to retain abrasive thereon during a portion of each revolution thereof,

nand forcausing the abrasive'accumulated thereon to be discharged therefrom during another portion of each revolution, said abrasive supporting surfaces constituting a continuous annu-` lar wall, and said abrasive controlling meansV comprising a second hollow structure mounted for rotation about an axis which is inclined with respect to the axis of said first hollow structure vand co-operative with said wall to retain the abrasive thereon during a part of each revolution.

20. In an abrasive propelling device, a hollow structure rotatable lat high speed, said structure-providing abrasive supporting surfaces disn posed circularly around said structure and said surfaces facing toward the axis of rotationof said structure, means for feeding abrasive to the interior of said structure and'for depositing it upon said surfaces, and abrasive controlling means for causing each of said surfaces to retain abrasive.

thereon during a portion of each revolution thereof, and for causing the abrasive accumulated thereon to be discharged therefrom during another portion of each revolution, said abrasive control means comprising a second hollow' structure mounted for rotation about an axis which is inclined with respect to the axis of rotation of said first hollow structure, said lsecond hollow structure having an axially extending passage 'terminating' in an outwardly flaring surface for accelerating .the abrasive. l

, WALTER L. 

